1 /*******************************************************************************
2 * Project: BaBar detector at the SLAC PEP-II B-factory
4 * File: $Id: EvtDalitzResPdf.hh,v 1.2 2009-03-16 16:42:46 robbep Exp $
5 * Author: Alexei Dvoretskii, dvoretsk@slac.stanford.edu, 2001-2002
7 * Copyright (C) 2002 Caltech
8 *******************************************************************************/
11 * Pole compensating function for terms that exibit a resonant structure
12 * in one dimension only.
15 * -- ------------------
16 * pi (q-q0)^2 + g^2m0^2
18 * m is the mass of the resonance, g is its width. The approximation works well for a narrow
19 * resonance. It is also readily integrable over the Dalitz plot coordinate to produce
21 * Int = 1/pi atan((q-q0)/(g*m0))
24 #ifndef EVT_DALITZ_RES_PDF_HH
25 #define EVT_DALITZ_RES_PDF_HH
27 #include "EvtGenBase/EvtPdf.hh"
28 #include "EvtGenBase/EvtDalitzPoint.hh"
29 #include "EvtGenBase/EvtCyclic3.hh"
31 class EvtDalitzResPdf : public EvtPdf<EvtDalitzPoint> {
35 EvtDalitzResPdf(const EvtDalitzPlot& dp,double m0, double g0, EvtCyclic3::Pair pairRes);
36 EvtDalitzResPdf(const EvtDalitzResPdf& other);
37 virtual ~EvtDalitzResPdf();
40 EvtPdf<EvtDalitzPoint>* clone() const { return new EvtDalitzResPdf(*this); }
42 virtual EvtValError compute_integral(int N) const;
43 virtual EvtDalitzPoint randomPoint();
44 double pdfMaxValue() const;
48 virtual double pdf(const EvtDalitzPoint&) const;
55 EvtCyclic3::Pair _pair; // resonant pair